CN1330590C - Organic waste treatment - Google Patents

Abstract

A wastewater treatment method comprising adding at least one Cell Signaling Chemical (CSC) to a wastewater substrate, wherein the at least one CSC modulates activity of a microbial population in the wastewater substrate. In particular, methods of reducing odor in a wastewater treatment system, preventing corrosion of a wastewater treatment system, promoting microbial digestion of wastewater, controlling biogas production in a wastewater treatment system, promoting digestion of wastewater sludge, resuscitating microorganisms that are dormant in a wastewater substrate or microorganisms that are in a starvation or stationary phase, and controlling bacteria responsible for oxidizing or reducing nitrogen-containing compounds in a wastewater substrate are provided.

Description

Organic Waste Treatment

The present invention relates to a method of altering the activity of microflora in sewage at the cellular level by adding at least one cell signaling chemical agent.

The decomposition of sewage is a problem of global importance. The increasing trend of urbanization is a factor in the concentration of sewage in localized areas.

Wastewater treatment plants are usually located away from populated areas. With increasing urbanization, the distance that wastewater travels before it reaches the wastewater treatment plant for processing and the time it spends in the wastewater catchment system increases. Long retention times and high temperatures create major problems in sewage catchment systems as sewage rots. Putrid sewage is malodorous and difficult to process in sewage treatment plants (STP). This is partly due to the high levels of sulfides inhibiting the normal microbial activity associated with sewage breakdown. This results in wastewater that is not fully digested and thus contains a higher organic component. Such wastewater is a potential health and environmental hazard.

Putrid sewage produces unpleasant odors, such as those associated with hydrogen sulfide gas (rotten egg gas) and other malodorous gaseous substances. These odors are not only annoying, but also toxic in certain concentrations. High levels of dissolved sulfides (such as HS or _H2S ) in wastewater reaching the STP must be oxidized to sulfates (such as _SO4 or _H2SO4 ), increasing the energy required for oxidation _. High levels of dissolved sulfides also inhibit sewage digestion by aerobic and anaerobic methane-forming bacteria and thus may inhibit important components of the sewage decomposition process, which may lead to large amounts of sludge.

In environments such as sewage catchment systems, sulfur reducing bacteria are microbially active to form hydrogen sulfide gas (Equations 1 and 2).

S＝+2H ⁺ →H ₂ S (2)

Another group of bacteria may then convert the sulfide to sulfate, thus producing sulfuric acid (Equation 3)

In sewage catchment networks and sewage treatment plants, the formation of sulfuric acid leads to major corrosion problems (e.g. Equation 4). Corrosion caused by sulfuric acid is a major cause of infrastructure failure and degradation in these networks and plants.

H ₂ SO ₄ +CaCO ₃ →CaSO ₄ +H ₂ O+CO ₂ (4)

Chemical agents can be used to suppress odor and corrosion in sewage systems. Other chemicals can also be used to improve wastewater treatment. Examples of these chemical agents include acids or bases for adjusting pH, disinfectants, pesticides, antibiotics, surfactants, deodorants, fragrances, chelating agents, oxidizing agents, and oxygen.

Some chemical treatments rely on chemical reactions to reduce odor, corrosion, or microbial activity, while other chemicals are used to kill bacteria or specific groups of bacteria. Nutrients can optionally be added to improve the environment for specific groups of bacteria so that they can outcompete less desirable bacteria. Chemical buffers are used to improve sewage treatment, while deodorizers mask, absorb or react with odors.

In general, the suppression of odor and/or corrosion requires the addition of a large number of chemical agents, many of which increase the salt levels in wastewater. Oxygen or oxidants can be used to stimulate aerobic bacteria, facultative anaerobes and other aerobic microorganisms, thus outcompeting sulfur reducing bacteria using the same food source.

Simple and efficient wastewater treatment methods are needed to reduce or prevent the difficulties outlined above.

Many naturally occurring chemical agents are known to modulate the behavior of particular microorganisms or their communication with other microorganisms in a population. These chemicals are called Cell Signaling Chemica 1 (CSC). CSCs are diffusible signaling molecules that regulate gene expression through microbial cell surface or intracellular receptors. CSC is not a bactericide or an antibiotic, and does not cause lysis of bacteria. Similarly, CSC is not a nutritional supplement that can be added to overcome auxotrophs that can modulate microbial populations.

CSCs at specific concentrations are known to produce a range of responses in prokaryotic cells, such as autoregulation, stimulation of slow-growing or dormant microorganisms, quorum sensing, virulence, motility, biofilm formation, increased or decreased reproduction, and Increase or decrease in metabolic activity. A fundamental difference between CSCs and other chemical agents used for microbial control is that CSCs manipulate microbial responses at the cellular level by communicating signals. These CSCs are responsible for turning on or off the expression of specific genes at specific signal strengths. CSCs neither kill bacteria nor do they provide essential nutrients to increase or decrease the response of specific microorganisms. CSC is upregulated (speeded up) or downregulated (slowed down), reducing or disrupting communication signals between bacteria. This downregulation may even force bacteria to revert from a biofilm state to a planktonic (single-celled or free-floating phenotype) state. Instead, CSCs may upregulate (enhance) microbial communication signals. This enhanced signal strength can be used to allow planktonic bacteria to increase their rate of reproduction and metabolism, thereby exploiting available food resources. Enhanced signal strength (CSC) also allows planktonic bacteria to proliferate, attach to surfaces, form microcolonies, threshold sensitivity, and form mature biofilms.

The response of a particular species of bacteria to a particular CSC and the strength of its signal are transient if the particular signal and its strength cannot be maintained. Both signal strength and signal type are important in the maintenance of specific gene expression. If the specific signal and signal strength cannot be maintained, the stimulated gene will usually revert to the non-stimulated state within a period of time ranging from minutes to hours. CSCs decompose rapidly in the environment and must therefore continuously produce specific signal concentrations to elicit specific microbial responses.

Different microorganisms respond to different cell signaling chemicals at different chemical cell signal strengths. For example, Gram-negative bacteria respond to N-acyl homoserine lactones, while Gram-positive bacteria respond to specific peptide pheromones, usually via a two-component signal transduction system to histidine kinases. The effects of CSCs have been observed previously in a series of laboratory experiments, and they have been used to inhibit biofilm formation in marine environments. These tests and uses have been described in Keleerebezem M, QuandriLEN, Kuipers OP abd deVos WM. "Quorum sensing by peptide ide pheromones and two-component signal-transduction system in Gram-positive bacteria" Molecular Microbiology, 1997, Vol 24 No.5, pp 895 -904; deNys R, Rice S, Manefield M, Kjelleberg S, et al. "Cross talk in bacterialextrace1lular signals" Microbial Biosystems: New Frontiers. Proceedings of the 8th International Symposium on Microbial Ecology. Bell CR, Brylinsky, Johnson-Green P( ed)., Atlantic Canada Society for Microbial Ecology, Halifax, Canada 1999; Lazazzera BA, Grossman AD "The ins and outs of peptide signaling" Trends Microbiol., 1998 Jul: 6(7): 288-94; Salmond GP, Bycroft BW, Stewart GS, Williams P "The bacterial 'enigma': cracking the code of cell to cell communication" MolMicrobiol., 1996 Feb;19(3):649; Buchenauer H. "Biological control of soil-bourne diseases by rhizobacteria" Zeitschrift-fuer -Pfanzenkrankheiten und Pflanzenschultz, July, 1998; 105(4) 329-384; Kazlauskas R, Murphy P T, Quinn R J. Wells RJ "A new class of halogenated lactones from the red algae Delisea fimbriata (Bonnemaisoniace (1.97ae)" Lett. 1:37-40; Antifouling Compositions, Steinberg et al. US Patent No. 6,060,046, May 9, 2000.

The present invention relates to the use of CSCs to manipulate, mediate or regulate communication signals between bacterial species or populations in sewage, sewage catchments or STPs. This enhances or disrupts the normal communication pathways for bacteria to communicate with each other. Using this technique, cellular signaling that enables motility, threshold sensitivity, and biofilm formation may be disrupted. This disruption may revert the bacteria to a planktonic state and substantially downregulate their activity. Alternatively, other signals or signal strengths may be used to initiate or enhance cellular signaling leading to resuscitation, motility, increased metabolic activity and proliferation rate, threshold sensitivity and biofilm formation. Advantageously, very small amounts of CSC can be used to elicit the desired response.

In one embodiment, the present invention provides a method of sewage treatment, comprising: adding at least one cell signaling chemical agent to the sewage substrate, wherein at least one cell signaling chemical agent regulates gene expression in microbial cells or regulates microbial cell or communication signals between microbial cell populations to regulate the activity of at least one microbial population in a sewage substrate; wherein said microbial population is selected from aerobic, facultative anaerobic and anaerobic bacteria.

The activity of microbiota can be altered or modulated by manipulating individual microorganisms in the population by controlling the levels of signaling chemicals within or between cells. Alternatively, the activity of the microbiota can be altered or modulated by manipulating the microbial colony or population by controlling the levels of intercellular signaling chemicals in the medium. Specific microbial activities that can be manipulated by CSCs include cell-to-cell communication, threshold sensitivity, motility, motility of bacteria, symbiotic relationships with multicellular organisms, cellular metabolic rate, production of metabolites, cell division and association, Cell recovery, formation of biofilm colonies, entry into quiescent or dormant phases, discrete and diverse metabolic processes consistent with cell density, bioluminescence, and production of antibiotics, surfactants, and enzymes.

The term "cell signaling chemical" (CSC) refers to a chemical agent capable of manipulating the behavior of specific microbiota through intracellular or extracellular signaling within or between prokaryotic cells. At specific CSC intensities, specific species of microorganisms respond to signals at the intracellular level through gene expression. These signals are often used to help specific species of microbes maximize the use of resources. Different CSCs may also mimic, block, inhibit, or interfere with communication signals between specific microbes or groups of microbes. For example, cell signaling chemicals may act by binding to cell surface receptors and inhibiting or blocking other CSCs, thereby altering communication between microorganisms in a population. Such CSCs often reduce the response of specific microorganisms or populations and reduce their ability to utilize resources. CSC is also responsible for regulating the activity of microorganisms by mediating cross talk between microorganisms. Communication appears to be important in alleviating starvation and stationary phase responses and in the resuscitation of dormant or quiescent bacteria.

As used herein, the term "up-regulation" refers to the use of at least one CSC with sufficient signal strength to increase the microbial activity of at least one microorganism (increase in one or both of the metabolic rate and the reproductive rate of the bacterium), especially the function of the microorganism. Synergy leads to possible formation of an adherent layer on the surface, possible formation of microcolonies, possible threshold sensitivity and formation of mature biofilms.

As used herein, the term "down-regulation" refers to the use of at least one CSC with sufficient signal strength to reduce microbial activity (reduction in one or both of the metabolic rate and reproductive rate of the bacteria), possibly destroying and dispersing the bacteria formed on the surface. Microbial attachment layer, possible disruption and dispersion of microcolonies formed by at least some species of bacteria, reduced threshold sensitivity of at least some species of bacteria, and reduction of biofilm formation by at least some species of bacteria. In many cases, down-regulation will mean disruption of the biofilm complex, in particular bacteria or bacterial species reverting to a planktonic state, yet still viable and culturable. Downregulation may be due to reduced signal strength, interference with the signal or pre-existing signal, or competition for signaling receptor sites on the bacterium.

The term "cross talk" as used herein refers to the response of microorganisms induced by a series of CSC signals and/or signal strengths. Differential pheromone and furanone signals and/or signal strengths are used to transmit or disrupt signals between particular members of the flora (same species) or community (different species). Communication is very important in enhancing or interfering with the communication networks of competing bacteria. Communication enhances or reduces the up- or down-regulation of bacteria, thereby enhancing or reducing the ability of the microbiota or community to utilize resources. Communication is also important in preventing bacteria from entering starvation or stationary phases and in bacterial resuscitation.

It is particularly useful in wastewater treatment to alter the activity of microbiota, stimulate microorganisms that decompose organic waste, inhibit or downregulate the activity of microorganisms that produce toxic and malodorous gases such as sulfides, greenhouse gases such as biogas or corrosive by-products such as sulfuric acid . It can also be used in specific locations, such as in sewage catchments, to inhibit the formation of microbial populations that support biofilms of sulfur-reducing bacteria.

Specific CSC, control pheromones, such as furanones, when applied to wastewater catchments at specific concentrations, can be used to downregulate bacterial motility and prevent subsequent biofilm formation. Furanones can be used to detach, detach or remain in the planktonic (single-celled) state of bacteria. This is especially important in controlling odors associated with sulfur reducing bacteria and other odor forming bacteria. In the planktonic state, the sulfur-reducing bacteria will produce only about one-thousandth the level of sulfide that they are able to produce in the biofilm state.

High levels of dissolved sulfide reaching the head of work of the STP interfere with wastewater treatment. Minimizing the generation of sulfides in the wastewater catchment by using CSC means that only very low levels of sulfides will reach the STP and these sulfides will not have a significant adverse effect on the wastewater treatment process. Low levels of sulfide in catchment water will minimize the high levels of corrosion often associated with malodorous sewage.

Specific CSC, stimulating pheromones such as N-acyl homoserine lactone peptides and specific histidine protein kinase pheromones are particularly useful in the treatment of sewage. They are used together with other substances at specific dosage rates to upregulate or stimulate the metabolic and reproductive rates of one or both of aerobic and anaerobic bacteria, thereby promoting the breakdown of sewage. By manipulating the microbial population, factors such as the level of aerobic and anaerobic decomposition and even the production of biogas (a greenhouse gas) can be controlled.

CSCs typically include bacterial pheromones, eukaryotic hormones and diffusible communication molecules or their derivatives. CSCs may be naturally occurring or possibly synthetic. Bacterial pheromones include such as N-acyl homoserine lactone (AHL), pheromone peptides including histidine protein kinases, N-acetylated, C-amidated D-amino acid hexapeptides including D-tyrosine and/or or D-amino acid peptides of D-isoleucine, cyclic dipeptides, hydrophobic tryamines, fatty acid derivatives and furanones, such as halogenated, hydroxylated or alkylfuranone compounds. CSCs can also be eukaryotic hormones, including auxins, such as indole-3-acetic acid, cytokinins, or cytokines with cytokinin activity such as 6-(γγ-dimethylallylamino)purine, Zeatin and 6-benzylamino-purine, ethylene gas, gibberellins and abscisic acid. Diffusible communication molecules are obtained from plant, animal, algal or microbial sources and have cell signaling functions, or synthetic derivatives of these compounds. Other useful CSC compounds are rhodamine 123 and methyl 3-hydroxypalmitate. Furanones useful in the present invention include 4-acetoxy-2,5-dimethyl-3(2H)-furanone, 4-hydroxy-5-methyl-3(2H)-furanone, 4-hydroxy -2,5,-Dimethyl-3(2H)-furanone, 4-hydroxy-2-ethyl-5-methyl-3(2H)-furanone, 4-hydroxy-5-ethyl-2 -Methyl-3(2H)-furanone, 4-hydroxy-5-methyl-3(2H)-furanone, 4-methoxy-2,5-dimethyl-3(2H)-furanone , 4-ethoxy-2,5,-dimethyl-3(2H)-furanone, 4-butyryloxy-2,5,-dimethyl-2(3H)-furanone, 4- Hydroxy-2,5-dimethyl-3(2H)-furanone, (S)-(+)-5-hydroxymethyl-2(5H)-furanone, (R)-dihydro-3-hydroxyl -2(3H)-furanone, (S)-dihydro-3-hydroxy-2(3H)-furanone, (R)-dihydro-4-hydroxy-2(3H)-furanone, (R) -Dihydro-5-(hydroxymethyl)-2(3H)-furanone, 3-chloro-4(bromochloromethyl)-5-hydroxy-2(5H)-furanone, 3-chloro-4- (Dibromomethyl)-5-hydroxy-2(5H)-furanone, 3-bromo-4-(dibromomethyl)5-hydroxy-2(5H)-furanone, 3-chloro-4-( Dichloromethyl)-5-hydroxy-2(5H)-furanone and 3-chloro-4-(dichloromethyl)-2(5H)-furanone. Acetyl homoserine lactone (AHL) includes N-(3-oxohexanoyl)-L-homoserine lactone (OHHL), N-butyryl-L-homoserine lactone (BHL), N-hexanoyl- L-homoserine lactone (HHL), butyryl homoserine lactone, hydroxybutyryl homoserine lactone, octanoyl homoserine lactone, 3-oxooctanoyl homoserine lactone, 3R-hydroxy-7-cis - Myristenoyl-homoserine lactone and 3-oxododecanoyl homoserine lactone. Suitable histidine protein kinases include HPK 1a, HPK 1ai, HPK 1b, HPK 1c, HPK 2a, HPK 2b, HPK2c, HPK 3a, HPK 3b, HPK 3c, HPK 3d, HPK 3e, HPK 3f, HPK 3g, HPK3h , HPK 3i, HPK 4, HPK 5, HPK 6, HPK 7, HPK 8, HPK 9, HPK 10 and HPK 11 families.

Pheromones are small molecules secreted by one specific prokaryote and received by another individual of the same species in which they transmit specific behavioral signals. At specific signal strengths (chemical concentrations), bacteria may be motile, threshold sensitive, and biofilm-forming. Conversely, if the signal intensity decreases, bacteria may detach, shed and resume their planktonic state. Pheromones are positive signals that up- or down-regulate microbial responses.

In contrast furanones are signaling blockers. That is, substances that compete with pheromones for the same signaling site or otherwise block pheromone signaling. At a specific signal strength, furanone was able to prevent at least one type of bacteria from forming a colony or it could kill the colony by interrupting the normal pheromone communication between bacteria.

There are many pheromone and furanone signals and communication between bacteria seems to be universal. Pheromones are important in territory markers, with specific pheromone signals at specific intensities eliciting specific responses in bacterial species, allowing one species to outcompete another for an environmental niche. Furanone at low signal intensity has a role in alleviating starvation and stationary phase, possibly by blocking the pheromone signal that transmits bacteria to enter starvation or stationary phase.

Microbial groups that can be manipulated by the methods of the invention include Gram-positive bacteria, Gram-negative bacteria, cyanobacteria, autotrophic bacteria (photosynthetic and chemoautotrophic), heterotrophic bacteria, and nitrogen-fixing bacteria. The invention is also useful for manipulating aerobic, facultative anaerobic and anaerobic bacterial populations; and is particularly useful for manipulating bacterial populations producing malodorous gases including hydrogen sulfide (by sulfur and sulfate reducing bacteria) and for converting sulfide into Bacteria of sulfuric acid. The invention can also be used to manipulate ammonia-forming, nitrite-forming, nitrate-forming, denitrifying and methane-forming bacterial populations.

In one embodiment of the invention, the activity of Gram-negative bacteria is enhanced or inhibited by adding at least one CSC. Addition of at least one CSC, such as N-acetyl homoserine lactone, to a sewage substrate at a specific dosage rate that modulates, enhances, inhibits and/or maintains the function of specific microbial activities including threshold sensitivity, motility and biofilm production level. Conversely, at least one other CSC, such as a halogenated furanone, can be added to sewage substrates at specific dosage rates to down-regulate functions such as motility and biofilm attachment. Specific furanones at specific dosage rates are used to interfere with interspecies communication, thus leading to dissemination of biofilms, shedding and maintenance of bacteria in their planktonic state.

In another embodiment of the invention, the activity of Gram-positive bacteria is enhanced or inhibited by adding at least one CSC. In this embodiment, at least one specific CSC is a peptide pheromone that activates the histidine protein kinase receptor of the two-component signal transduction system. Specific dosage rates of at least one CSC are used to up-regulate or down-regulate, enhance or reduce, initiate and/or maintain specific functional levels of microbial activity, such as motility, threshold sensitivity, and biofilm production. Other CSCs, such as antimicrobial peptides and furanones that inhibit the two-component signaling pathway histidine-protein kinase response modulator, were used at specific dose ratios to disrupt pheromone peptide signaling and thus downregulate motility and biofilm attachment. Effect. Such peptides include N-acetylated D-amino acid hexapeptides. Specific furanones at specific dose rates interfere with interspecies communication thus causing biofilm dissemination, shedding and maintenance of bacteria in their planktonic state.

In another aspect of the invention. At least one CSC may affect domains of histidine kinase protein receptors (signal receptors) or response regulator proteins, controlling phosphorylation or dephosphorylation of regulatory domains. Phosphorylation stimulates or represses the transcription of specific genes. However, the phosphorylation response is transient, with response regulator proteins reverting to a non-stimulated state within a period ranging, for example, from seconds to hours. In order to maintain the desired state, it is important to maintain at least one CSC at sufficient signal strength to obtain the desired signaling response.

In another aspect of the invention, at least one CSC may downregulate the swrA gene and thereby reduce the production of lipoprotein biosurfactant required for motility.

In another aspect of the invention, at least one CSC may be a cyclic dipeptide that interferes with acyl homoserine lactone (AHL), possibly by competing with AHL for the bacterial binding site.

In another aspect, at least one CSC may be a furanone applied at a non-growth inhibitory concentration that would minimize or eliminate the effects of stress resistance, senescence, or lack of culturability caused by carbon starvation. At least one CSC may also contain a supernatant that is used in combination with furanone to avoid loss of culturability induced by carbon starvation or other stresses.

In another aspect, at least one furanone (CSC) may be added to interfere with interspecies communication during motility of the mixed culture. This reduces the production of serrawettin W2, which is necessary for surface trafficking of differentiated motile cells.

In another aspect, at least one CSC can be used to control extracellular enzyme production and/or Harpin _Ecc production, or to control genes responsible for post-transcriptional regulation, thus controlling changes in phenotype or phenotypic expression.

In yet another aspect of the invention, at least one CSC is used to control gene expression of a particular microorganism. There are a number of different gene expressions that can be enhanced or decreased by using specific CSCs and or signal strengths. These include, but are not limited to, the production of luminescence, toxins, antibiotics, enzymes, polysaccharides, and surfactants. Microbially produced enzymes and microbially produced surfactants, or the absence of these products, play an important role in sewage transport or digestion. Toxins and antibiotics are more regional markers and thus also play a role in the dominance of certain types of microorganisms. Thus by using at least one CSC to control gene expression, the microbial dominance and the products produced by this dominance are altered and thus the sewage digestibility.

In another aspect, at least one CSC can be used to interfere with a gene responsible for the formation and/or signal strength of 3-oxydecanoyl HSL and/or butyryl HSL. 3-Oxylauroyl HSL, a type of CSC, produced by at least some microorganisms is important in regulating the production of polysaccharides required for the adhesion of biofilms to at least some surfaces. Butyryl HSL leads in at least some microorganisms to the production of polysaccharides required in biofilm formation. 3-Oxydecanoyl HSL and/or butyryl HSL thus play an important role in the formation and/or attachment of biofilms for at least some microorganisms. Interfering with these signals or signal strengths is very important in minimizing biofilm attachment and/or biofilm formation.

In another aspect, at least one CSC may be a mimic of a bacterial pheromone or it may elicit a genetic response elicited by a bacterial pheromone. That is, when applied to the culture medium at a specific concentration, the mimic will provide an extracellular signal that elicits the same response as the bacterial pheromone.

In another aspect, at least one CSC can be a mimetic of bacterial furanone. When applied to sewage at specific concentrations, this mimic will provide an extracellular signal that elicits the same response as bacterial furanones in sewage.

In another aspect, the concentration (signal strength) of at least one CSC will be a critical factor in the activation of a particular receptor protein leading to expression of a particular gene.

Sewage includes carbonaceous and nitrogenous wastes. Carbonaceous waste includes compounds containing carbon and hydrogen atoms and possibly other atoms such as oxygen, nitrogen, sulfur and phosphorus. Nitrogenous wastes include compounds containing nitrogen atoms and other atoms such as hydrogen, carbon and oxygen. Nitrogenous wastes include urea, uric acid, ammonia, nitrates and nitrites. Sewage contains a variety of different microbial populations, including aerobic, facultative anaerobic and anaerobic bacteria.

The composition of sewage varies depending on what is discharged into the sewage catchment network. In addition, the flow rate of sewage in the sewage catchment network is variable, and this determines the residence time of sewage in the sewage catchment network. For example, at night, the volume of sewage entering the sewage catchment network is low and the flow rate tends to be slow. During the day, more sewage enters the sewerage network, and its composition may vary, since industrial waste may be discharged into the network just as human waste. Furthermore, the flow rate of the sewage is also increased because a larger volume of waste is discharged into the sewage catchment network.

The dosage level of CSC needed will depend on the amount of sewage substrate, flow rate, biochemical oxygen demand (BOD)/chemical oxygen demand (COD) load and bacterial composition. The bacterial composition of sewage substrates can be determined using standard plate counts to determine bacterial species or types. The desired dose level of CSC can be determined by assessing the bacterial composition, amount and flow rate, thus the dose level may vary during, for example, a 24 hour treatment period.

Typically, CSC can be added to the sewage substrate at a dosage level of 1 nanogram per liter or kilogram of sewage to 1 gram per liter or kilogram of sewage. Furanone in the range of 2.5 μg/m ² to 25 g/m ² is effective in preventing the formation or adhesion of biofilm in sewerage pipes.

One or more CSCs can be added to the sewage substrate. A single CSC of a particular signal strength or concentration may alter the behavior of a single group of microbes (phenotypic expression) in a sewage substrate, or it may independently change the behavior of more than one group of microbes (phenotypic expression) in a sewage substrate. Alternatively, mixtures of CSCs that may collectively alter a single microbial population, or that may independently alter the behavior of more than one microbial population in a sewage substrate, may be added to the sewage substrate. A mixture of CSCs can be added such that a second CSC supplements or supplements the activity of the first CSC. For example, by enhancing the response or preventing feedback inhibition that might desensitize the microbial cell to the activity of the first CSC.

Alternatively, furanones and antimicrobial peptides (CSC) can be added to sewage in catchments to prevent motility and surface colony formation through biofilms. These CSCs may be specific or general in their application to maintain bacteria in a planktonic state. Additional specific CSCs at specific concentrations (signal strengths) can be added to wastewater for mediating starvation and stationary phase responses. This communication between different bacterial signals (CSC) and CSC signal strength can be maintained during sewage transport in sewage catchment pipes. When the sewage reaches the working end of the STP, according to the design requirements of the STP, different signals or signal strengths can be used to change the microbial population, so as to rapidly accelerate the digestion (decomposition) of sewage by aerobic or anaerobic bacteria.

Advantageously, at least one CSC may be added to a sewage substrate in a composition comprising a growth promoting medium that supports or enhances the growth of desired microorganisms in the sewage substrate resulting in an increased decomposition rate. These growth promoting media may contain carbohydrates, protein substances, amino acids, fats and oils, vitamins and minerals. However, it must be recognized that CSCs are major regulators of microbial activity. Growth medium supplements only eliminate deficiencies of growth-limiting factors.

Compositions containing CSCs may also contain chemicals that complement or complement the effects of CSCs by reacting with toxic or undesirable by-products of the decomposition process, thereby rendering them non-toxic or more desirable products. For example, compounds can be added that will mediate the effects of fatty acids or other deleterious compounds, or adjust the pH and make the medium more or less suitable for a particular bacterial colony or species. Alternatively, CSC can be added to the sewage substrate along with oxygen or oxides. CSC stimulates the growth and metabolic rate of aerobic bacteria, while the supplied oxygen eliminates the lack of oxygen as a growth limiting factor.

At least one CSC or a composition comprising at least one CSC may be added to the separated sewage substrate. Alternatively, they may be added at specific points along the sewage catchment network, at sewage treatment plants, or may be added to the sewage effluent. The at least one CSC or composition containing at least one CSC can be added in the form of a bolus, or can be added continuously or intermittently by simple drip or pump system. The at least one CSC or the composition containing at least one CSC may be in spray or drop form and may be added to the sewage by spraying or dripping onto the surface of the sewage. When adding at least one CSC or composition containing at least one CSC, it may be by mixing the CSC with the substrate to help disperse the at least one CSC throughout the sewage substrate. It can also be a method of monitoring the concentration of CSC added to the organic waste substrate to ensure that the desired concentration is maintained, and that more CSC can be added if the concentration drops below the desired level, or the addition can be suspended if the concentration rises above the desired level. CSC. Those skilled in the art will be able to determine the appropriate method and amount of adding CSCs or compositions containing them to the substrate.

The at least one CSC or the composition containing the at least one CSC may be in the form of a liquid, solution, powder, granule, pellet or gas. Compositions containing at least one CSC may also contain other suitable carriers or adjuvants. The composition may also contain components such as dispersants, binders, wetting agents and other surfactants, fillers or other components that supplement and augment the activity of the CSC. Advantageously, the CSC is usually added to the sewage of the network catchment by a peristaltic pump, however, the CSC can also be added in the form of slow release pellets or granules which allow the CSC to be released into the substrate over a certain period of time. Alternatively they may be added to the system in the form of a gas or dissolved in a liquid state.

In a preferred aspect of the present invention, a method for treating sewage substrates is provided, comprising: adding at least one cell signaling chemical agent (CSC) to sewage substrates, wherein at least one CSC enhances aerobic, anaerobic Activity of aerobic or facultative anaerobic microbiota.

This aspect of the invention is particularly useful in upregulating microbial activity and thereby increasing the rate of sewage breakdown in sewage treatment plants. This can also be used to facilitate the revival of dormant, non-growing or slow-growing microorganisms that aid in the decomposition of sewage. These processes can be further enhanced by the addition of cell signaling chemicals in the form of compositions containing growth-promoting media that correct possible nutritional imbalances affecting specific microbiota by limiting the effects of CSCs.

In yet another preferred aspect of the present invention, a method for reducing microbial activity in a sewage catchment network is provided, comprising: adding at least one cell signaling chemical (CSC) to the sewage catchment network, wherein the sewage catchment network Adding at least one CSC to down-regulate the activity of aerobic, facultative anaerobic and anaerobic microorganisms in the sewage substrate by regulating gene expression in microbial cells or regulating communication signals between microbial cells or between microbial cell groups.

This aspect of the invention is particularly useful in reducing the breakdown of sewage in sewage catchment networks and in providing fresher sewage to sewage treatment plants. The arrival of fresh sewage at the sewage treatment plant allows to optimize the aerobic decomposition of the sewage according to the engineering design criteria of the sewage treatment plant.

In another preferred aspect of the present invention, a method for reducing odor in a sewage treatment system is provided, comprising: adding at least one cell signaling chemical agent (CSC) to the sewage treatment system, wherein at least one cell signaling chemical agent passes through Regulate gene expression in microbial cells or regulate communication signals between microbial cells or between microbial cell groups to inhibit (down-regulate) the activity of odor-producing microorganisms or increase (up-regulate) the activity of other microbial groups in the sewage treatment system, so that other Microbiota outcompete odor-producing microbes using the same food source.

The term "sewerage system" as used herein refers to sewage catchment networks and sewage treatment plants.

This aspect of the invention is particularly useful in the reduction of malodorous sulfide gases in decomposed sewage, especially hydrogen sulfide gas produced by the activity of sulfur or sulfate reducing bacteria. These gases may be produced in sewage catchment networks or in sewage treatment plants. The activity of other microbiota may be enhanced, thus allowing these microbes to outcompete sulfur reducing bacteria using the same food source.

Addition of at least one CSC to a sewage catchment network can downregulate the behavior of sulfur-reducing microbial populations leading to their detachment from biofilms or possibly detachment of biofilms causing bacteria to revert to their planktonic state, preventing motility or threshold sensitivity, Inhibit their reproduction and/or reduce their metabolic rate. Sulfur or sulphate-reducing bacteria in the planktonic form produce only about one-thousandth the sulphide that they produce in the biofilm form. Alternatively, at least one CSC may upregulate the behavior of desired microorganisms by stimulating motility, threshold sensitivity, increasing their reproductive and/or metabolic rate, allowing them to outcompete sulfur-reducing bacteria using the same food source.

In another preferred aspect of the present invention, a method for reducing or preventing corrosion of a sewage treatment system is provided, comprising: adding at least one cell signaling chemical agent to the sewage treatment system, wherein at least one cell signaling chemical agent regulates microbial cell To inhibit the activity of microorganisms that convert hydrogen sulfide into hydrogen sulfate (sulfuric acid) through the expression of genes within the cells or the regulation of communication signals between microbial cells or between microbial cell populations.

CSC may inhibit the production of dissolved sulfide and hydrogen sulfide gas, thereby eliminating a food source for the microbes, or may disrupt the communication signaling between sulfuric acid-producing bacteria and thereby down-regulate these bacteria, thereby reducing sulfuric acid production.

This aspect of the invention is particularly useful in preventing corrosion in sewage catchment networks and sewage treatment plants.

Yet in a further preferred aspect of the present invention, there is provided a method of inhibiting the formation or maintenance of biofilm in a sewage catchment network, comprising: adding at least one cell signaling chemical to the sewage catchment network, wherein at least one cell signaling Chemical agents inhibit group swimming, threshold sensitivity, or biofilm attachment of microbial populations by modulating gene expression within microbial cells or modulating communication signals between microbial cells or between microbial cell populations.

The term "quorum sensing" as used herein refers to the level of communication, ie the type and strength of signals between bacteria that determine whether the bacteria are still planktonic, swimming, forming colonies or forming biofilms. More specifically, when a threshold is reached, the phenotypic expression of bacteria changes as they change from a single-cell state to a colony or multicellular state. Threshold sensitivity occurs when large numbers of bacteria communicate cell-to-cell, regulating the transcription of multiple target genes in concert with cell density. Under natural conditions, threshold sensitivity is mediated by the production of one or more pheromones, and signal strength is a key factor in determining the presence or absence of a threshold, and changes the behavior of bacterioplankton by mediating gene expression in colonies.

The term "biofilm" as used herein refers to the slime that typically forms on surfaces of objects when bacteria form colonies. Of particular concern are:

- Causes expansive biofilms in sludge

- Biofilm formation on the walls of sewage catchment pipes and biofilm formation on sediments in sewage catchment pipes

Filamentous swollen biofilm complexes are formed in the sludge, which reduces the treatment capacity and settling capacity of activated sludge. This aspect of the invention is useful in reducing/preventing filamentous bulking of sludge and improving sewage treatment and sludge digestion. CSCs can be used to control the formation and/or maintenance of filamentous bacterial populations that cause swelling in sludge.

Since CSC disrupts the ability of bacteria to form an adhesive layer that adheres to the substrate and forms biofilms, or CSC prevents the formation of polysaccharides necessary for the formation of biofilms, CSCs can be added to sewage substrates to prevent biofilm formation and/or or attach to a surface. Since it prevents adhesion and/or production of polysaccharides essential for biofilm formation, furanones are used to block N-acyl homoserine lactones such as 3-oxo-decanoyl homoserine lactone and butyryl homoserine lactone or Mixtures thereof are a particularly useful aspect of the invention.

Biofilms formed on surfaces may contain sulfur-reducing bacteria as part of the biofilm complex structure. Since CSCs prevent the formation of malodors, hydrogen sulfide and other malodorous gases in sewage catchment networks, the use of CSCs to eliminate biofilms or to eliminate sulfur reducing bacteria from biofilms is an important aspect of the present invention.

When forming biofilms, microorganisms use a complex intracellular communication signaling (CSC) system. Disruption of intracellular communication signals (CSCs) can prevent biofilm formation or disperse biofilms since the communication signal or signal strength is not maintained. Preventing or dispersing specific biofilms containing anaerobic sulfur reducing bacteria in organic waste sewage catchments helps to control sulfur reducing microorganisms and thus control odor in sewage catchments and sewage treatment plants. The reduction in the level of dissolved sulfides in the influent sewage reaching the sewage treatment plant also improves the sewage treatment of the sewage treatment plant.

In yet another preferred aspect of the present invention, a method of improving microbial digestion of sewage in a sewage treatment plant is provided, comprising: adding at least one cell signaling chemical (CSC) to sewage in a sewage treatment plant or in a sewage catchment network , wherein at least one cell signaling chemical (CSC) enhances aerobic, Activity of anaerobic and facultative anaerobic bacteria.

This aspect of the invention is particularly useful in treating sewage as it reaches a sewage treatment plant. Advantageously, the increased activity, reproduction and/or metabolic rate of aerobic and facultative anaerobic bacteria facilitates microbial digestion of sewage, improving the quality of sewage effluent and reducing sludge volume. Particularly useful in this aspect of the invention are AHL, pheromone peptides, N-acetylated, C-amidated D-amino acid hexapeptides, D- Amino acids, cyclic dipeptides, hydrophobic tyramides, lipopeptide biosurfactants, fatty acid derivatives, antimicrobial peptides, and furanones. A particularly preferred CSC is AHL.

In yet another preferred aspect of the present invention, a method of controlling biogas production in a sewage treatment plant is provided, comprising: adding at least one cell signaling chemical (CSC) to the sewage substrate in a sewage catchment network or a sewage treatment plant ), wherein at least one cell signaling chemical (CSC) increases or inhibits the activity of anaerobic and methane-forming bacteria by modulating gene expression within microbial cells or modulating communication signals between microbial cells or between microbial cell populations.

This aspect of the invention is particularly useful in controlling biogas production. This is desirable since biogas is a "greenhouse gas". Better control of biogas production could facilitate its capture and conversion of this gas to carbon dioxide and water by burning it.

In yet another preferred aspect of the present invention, there is provided a method of controlling bacteria that cause oxidation or reduction of nitrogenous compounds in a sewage substrate, comprising: adding at least one cell signaling chemical (CSC) to the sewage substrate , wherein at least one CSC regulates the activity of ammonia-producing bacteria, nitrite-producing bacteria, nitrate-producing bacteria, or denitrifying bacteria by modulating gene expression within microbial cells or modulating communication signals between microbial cells or between microbial cell populations active.

Specific CSCs or compositions of CSCs and/or specific CSC signal strengths can be used to upregulate or downregulate bacteria responsible for ammonification, nitrification and denitrification of sewage. This aspect of the invention is particularly useful in controlling a range of air and water environmental pollutants. N-acyl homoserine lactones, such as 3-oxo-decanoyl homoserine lactone and butyryl homoserine lactone or mixtures thereof are particularly useful in the upregulation of this aspect of the invention, while halogenated furanones, hydroxylated Furanones and alkylfuranones are particularly useful in the downregulation of this aspect of the invention.

In yet another preferred aspect of the present invention, a method of improving sewage sludge digestion is provided, comprising: adding at least one cell signaling chemical (CSC) to a sewage substrate, wherein at least one cell signaling chemical is regulated by Gene expression within microbial cells or regulation of communication signals between microbial cells or between microbial cell populations enhances the activity of aerobic or anaerobic bacteria.

This aspect of the invention is particularly useful in increasing the digestibility of sewage sludge by aerobic or anaerobic non-sulfur reducing bacteria, thereby reducing sludge volume and odor.

In another aspect of the present invention there is provided a method of reviving dormant microorganisms or microorganisms in a starvation or stationary phase in a sewage substrate, comprising: adding at least one cell signaling chemical (CSC) to the sewage substrate, at least one of which Cell signaling chemicals (CSCs) stimulate the activity of dormant, starved or quiescent microorganisms by modulating gene expression within microbial cells or by modulating communication signals between microbial cells or between microbial cell populations.

This aspect of the invention revives desired microorganisms that are present but inactive in sewage. Sewage is often a toxic and hazardous environment for microorganisms. Toxic household and industrial chemicals poured into sewer pipes. These toxic chemicals often have adverse effects on microorganisms, causing them to spore form or simply downregulate into a dormant or stationary phase. The use of CSCs to upregulate and revive beneficial microorganisms is often very important in improving wastewater treatment.

Long-distance transport of sewage can lead to carbon starvation in sewage, again causing bacteria to down-regulate into a dormant or stationary phase, or spore form. It is important to use CSCs at one stage to alleviate carbon starvation by downregulating bacteria, followed by another stage using CSCs to upregulate and/or resuscitate bacteria in sewage catchments or wastewater treatment plants. This aspect of the invention is very important in mitigating the effects of carbon starvation stress and poor sewage treatment. A particularly preferred useful CSC in this aspect of the invention is furanone.

In another aspect of the present invention, there is provided a composition comprising a cell signaling chemical agent and a carrier or adjuvant, wherein the cell signaling chemical agent is N-(3-oxohexanoyl)-L-homoserine Esters, 3-Oxylauroyl Homoserine Lactone, Zeatin, 6-(γγ-Dimethallylamino)purine, 6-Benzylamino-purine, Methyl 3-Hydroxypalmitate, and Comb Moss Extract .

Throughout this specification, unless the context requires, the word "comprise" or variations of the word "comprising" and "comprising" shall be understood as meaning the inclusion of stated integers or steps or groups of integers or steps, but not the exclusion of others. A whole or a step or a group of wholes or steps.

Description of drawings

Figure 1 is a diagram showing the response of aerobic microorganisms in a sewage sample to biosol 1, a mixture of CSCs, in which the number of microorganisms was determined by standard plate count.

Figure 2 is a diagram showing the response of anaerobic microorganisms in sewage samples to biosol 1, a mixture of CSCs, in which the number of microorganisms was determined by standard plate count.

Figure 3 is a diagram showing the response of sulfur-reducing microorganisms to biosol 2, a mixture of CSCs, in sewage samples, where the number of microorganisms was determined by standard plate count.

Figure 4 graphically represents the response of aerobic microorganisms to the different CSCs listed in Table 1 in sewage samples in which the samples had been passed through the gas.

Figure 5 graphically represents the response of anaerobic microorganisms to the different CSCs listed in Table 1 in sewage samples in which the samples had been aerated.

Figure 6 graphically represents the response of sulfur-reducing microorganisms to the different CSCs listed in Table 1 in wastewater samples in which the samples had been passed through the gas.

Figure 7 graphically represents the response of aerobic microorganisms to the different CSCs listed in Table 1 in sewage samples where the samples were not aerated.

Figure 8 graphically represents the response of anaerobic microorganisms to the different CSCs listed in Table 1 in sewage samples where the samples were not aerated.

Figure 9 is a graphical representation of the response of sulfur reducing microorganisms to the different CSCs listed in Table 1 in wastewater samples where the samples were not aerated.

Figure 10 graphically represents the average amount of dissolved sulfide in wastewater samples during the period in which biofilm shedding and reduction was observed.

Example

Example 1

Methodology used to examine the effect of various CSC dose ratios

The methodology relies on well established NATA standard procedures (Australian, British or American standards) for standard plate (heterotrophic) microbial enumeration. Plate counts are performed by:

○ Aerobic bacteria

○ Anaerobic bacteria including facultative anaerobic bacteria and

○Sulphur-reducing bacteria

The sampling procedure relies on taking predetermined wastewater samples. The sewage sample is then divided into 800ml sub-sample. One of these small samples was left as is as a control, and the CSC used for the test was added to the other identical small sample in a specified amount (typically nanograms to mg/liter).

Each 800 ml subsample of effluent was then shaken thoroughly to ensure that the effluent mixed with the added CSC. The control sub-sample is also shaken in the same way for the same time to ensure consistency between the sub-sample.

Each small sample was then decanted into 4 identical 200ml samples called A, B, C and D.

A samples from each replicate were then subjected to the NATA standard procedure for standard plate counts.

If examining the response of aerobic microorganisms, aerate samples B, C, and D by injecting a small but steady stream of air through the air pump into the bottom of the samples and letting air bubble out through the sewage mixture for two minutes every four hours.

If examining anaerobic reactions, each 200 ml sample of B, C, and D was sealed with a sealing cap to prevent further air from entering the sample.

After 24 hours, B samples from each replicate were then subjected to the NATA standard procedure for standard plate counts in the same manner as the A samples.

After 48 hours, C samples from each replicate were then subjected to the NATA standard procedure for standard plate counts in the same manner as the A samples.

After 72 hours, D samples from each replicate were then subjected to the NATA standard procedure for standard plate counts in the same manner as the A samples.

Example 2

Using the procedure outlined in Example 1, CSC mixtures (Biosol 1 or 2) were added to sewage samples. The mixtures called Biosol 1 and Biosol 2 indicate what can be obtained with relatively fresh sewage samples collected at the working end of small sewage treatment plants. The results are shown in Figures 1 to 3.

The composition of Biosol 1 is:

0.05mg/L N-(3-oxohexanoyl)-L-homoserine lactone

0.05mg/L 3-Oxydecanoyl Homoserine Lactone

0.005mg/L N-butyryl-L-homoserine lactone

0.01mg/L Zeatin (Zeatin)

0.08mg/L 6(γγ-dimethylallylamino)purine

0.08mg/L 6-benzylamino-purine

0.1mg/L Methyl 3-Hydroxypalmitate

0.1g/L Comb moss (Delisea pulchra) extract (a known source of furanones)

Contents of half a 1000 mg multivitamin capsule

1g yeast extract

0.1g seaweed powder (as mineral) (Durvillea potatorun)

The mixture was made up to 1 L with deionized water. This mixture was added at a rate of 4 mg/L effluent.

The composition of Biosol 2 is:

0.005mg rhodamine

2g/L Comb Moss Extract (a known source of furanones)

0.005mg/L N-butyryl-L-homoserine lactone

Contents of half a 1000 mg multivitamin capsule

1g yeast extract

0.1g seaweed powder (as mineral) (Durvillea potatorun)

The mixture was made up to 1 L with deionized water. This mixture was added at a rate of 4 mg/L effluent.

Figure 1 shows that the CSC mixture (Biosol 1) initially inhibits the activity of aerobic microorganisms, followed by a large increase in the number of microorganisms, expressed as the number of colony-forming units. Controls showed microbial activity responding rapidly initially, but then failing to respond to available food sources.

Figure 2 shows that the CSC mixture (Biosol 1) caused a rapid increase in the anaerobic microbial population in the raw sewage.

Figure 3 shows that CSC mixture in Biosol 2 reduces the colony forming units of sulfur reducing bacteria. Although the control initially showed a decrease in sulfur reducing bacteria, the number of sulfur reducing bacteria increased after 28 hours of incubation.

Example 3

Using the procedure outlined in Example 1, wastewater samples were spiked with specific CSCs in vitro at specific dosage rates. Each sample contained the different CSCs listed in Table 1 below, and each sample was divided into 3 small samples. The first small sample was plated within 4 hours and analyzed for aerobic, anaerobic and sulfur reducing bacteria by standard plate count. The second and third small samples were ventilated every 4 hours and analyzed as small sample 1 at 24 hours and 76 hours, respectively. Colony densities of aerobic, anaerobic, and sulfur-reducing bacteria were determined by counting colony-forming units from each wastewater sample analyzed.

The results are shown in Figures 4-6. The results showed that different CSCs applied to sewage samples at different dosage rates were able to significantly alter the microbial population growth rate compared to the control.

Table 1

Group Joined CSC Amount added 1 No CSC-control - 2 Acyl homoserine lactone 0.5mg/L 3 Zeatin 6 (γγ-dimethylallylamino) purine 6-benzylamino-purine indole-3-acetic acid made into 1 liter 0.1mg/L0.1mg/L0.1mg/L0.1mg/L 4 cytokinin 1mg/L 5 Rhodamine 123 50ng/L

Example 4

The test of Example 3 was repeated, but the sample was not ventilated. The results are shown in Figures 7 to 9.

Example 5

CSC in the form of Biosol 2 was added to the fraction of the sewage catchment at a rate of 4 ppm. The hydrogen sulfide gas readings were halved within 24 hours and the levels of dissolved sulfides in the sewage decreased by 48% over the same period.

Example 6

Biosol 1 was added at a rate of 4ppm to the catchment water of a small sewage treatment plant with a high organic load of corruption. It increases the level of dissolved oxygen in the aerobic chamber from less than 1 ppm to approximately 7 ppm. It reduces the amount of sludge by 52% and the suspended solids in sewage by 80%.

The results of Examples 5 and 6 are consistent with those predicted from the in vitro tests.

Example 7

A mixture of halogenated furanones (1 g/L) in distilled water was added at a rate of approximately 0.5 mg/L using a peristaltic pump to the effluent flowing in a low-gravity sewer containing the established biofilm matrix. After one month the biofilm on the pipe walls was significantly reduced and bare patches of pipe were evident. Halogenated furanone mixtures detach biofilm from sewage pipe walls and affect biofilm formation.

Example 8

Equal mixtures of halogenated furanones, hydroxylated furanones, and alkylfuranones (1 g/L) and AHL (1 g/L) were mixed in distilled water and pumped using a peristaltic pump at approximately The ratio of 4ml mixture of the sewage flowing in the sewage pipe with small gravity is added to the sewage. After one month the biofilm on the pipe walls was significantly reduced and bare patches of pipe were also evident. The furanone mixture disrupted the AHL signal, detached the biofilm from the sewage pipe walls and affected the biofilm formation.

Example 9

Delicia pulchra extract (collected from Cape Banks NSW, cooled and freeze-dried within 24 hours) was prepared by vitamising and extracting CSC from Delicia pulchra using dichloromethane. Extracts and crude fibers are previously reduced in vacuum. 10 g fiber and extract per liter of water, followed by vitaminization for 20 minutes, with enough ascorbic acid to lower the pH of the mixture to 3.5. The liquid was allowed to settle for 2 hours and the supernatant collected for use. This extract of known furanone origin was added to the sewage pipes for 4 weeks at a rate of approximately 4 ml per liter of sewage flowing in the pipes. After 4 weeks the extract detached the biofilm from the sewage pipes and affected the formation of biofilm.

Examples 7, 8 and 9 were also used to measure the effect on dissolved sulfide production. Dissolved sulfides in the sewage initially rose and then the level of dissolved sulfides decreased. The initial rise in dissolved sulfide was attributed to the high level of dissolved sulfide in the shed biofilm. The reduced dissolved sulfide production was attributed to a reduction in biofilm and a change in the biofilm microbial matrix. See Table 2 and Figure 10.

Table 2

sky Average results ppm for trials 7, 8 and 9

1 18 2 twenty one 3 17 4 twenty two 5 twenty three 6 19 7 14 8 16 9 11 10 13 11 9 12 10 13 10 14 7 15 4 16 6 17 4 18 5 19 4 20 3 twenty one 1 twenty two 3 twenty three 1 twenty four 2 25 2 26 1 27 1 28 1

Example 10

The halogenated furanone mixture (1 g/L) was added to each liter of extract Delicia pulchra. This mixture was added at a rate of approximately 4 mg/liter to the pumped sewage flowing in the low pressure sewage mains via a pumping station. This pressure main contains an established biofilm matrix. Sewage is anaerobic when it exits the pressure main and becomes very smelly when it flows into the gravity main. The gas is believed to consist primarily of hydrogen sulfide, but other malodorous gases such as mercaptans, indole and skatole are present. The level of hydrogen sulfide gas at the end of the pressure header averaged around 180 ppm before adding the above mixture. One week after the addition of the above mixture, the level of hydrogen sulfide gas had decreased to an average of 47 ppm. One month after adding the mixture, hydrogen sulfide levels had decreased to an average of 4 ppm. Although not specifically examined, mercaptan, indole and skatole-like odors were significantly absent.

An "OdaLog" (0-1000 ppm hydrogen sulfide) gas logger was suspended in the manhole at the end of the pressure main for 2 hours and the hydrogen sulfide gas level was measured 24 hours. The average reduction in hydrogen sulfide gas levels was calculated from these data.

Example 11

A mixture of halogenated furanones (1 g/L) was added to each liter of Delicia pulchra extract. This mixture was added at a rate of approximately 4 mg/liter to sewage flowing in sewage pipes containing an established biofilm matrix. The pipes contain sloppy sewage, but are aerated when the sewage is poured into the wet pump well. The _NO2 released into the pump well chamber at the end of the pipe was measured with a nitrogen dioxide gas data logger for 4 days from 5:40 am to 9 am. Although the levels of nitrogen dioxide were different from what would be expected when the above mixture was added to the wastewater samples, the average reduction was about 70%.

table 3

time (morning) NO ₂ ppm without mixture (control) NO ₂ ppm plus mixture Percent change in NO ₂ production 5.406.006.206.407.007.207.408.008.208.409.00 19.6911.7917.5032.7730.8914.2911.9616.9620.4525.8917.41 7.503.7510.6316.8817.779.820.000.891.790.000.00 38% 32% 61% 51% 58% 69% 100% 95% 91% 100% 100%

Example 12

The same mixture used in Example 11 was sprayed on or around the smelly men's urinal. The odor was eliminated within an hour. This indicates that urea cannot be converted to ammonia which is the main source of odor around old urinals.

Claims (49)

1. Sewage treatment method, comprising: adding at least one cell signaling chemical agent to the sewage substrate, wherein said at least one cell signaling chemical agent regulates gene expression in microbial cells or by regulating microbial cell or microbial cell population to regulate the activity of at least one microbial population in the sewage substrate; wherein said microbial population is selected from the group consisting of aerobic, facultative anaerobic and anaerobic bacteria. 2. The method according to claim 1, wherein said at least one cell signaling chemical agent is a bacterial pheromone or a eukaryotic hormone. 3. The method according to claim 2, wherein the bacterial pheromone is selected from the group consisting of N-acyl homoserine lactones; pheromone peptides; N-acetylated, C-amidated D-amino acid hexapeptides; comprising D-isoleucine D-amino acid peptides of acids and/or D-tyrosine; cyclic dipeptides; hydrophobic tyramines; fatty acid derivatives and furanones. 4. The method according to claim 2, wherein the eukaryotic hormone is selected from the group consisting of auxins, cytokinins, cytokines, ethylene gas, gibberellins and abscisic acid. 5. The method according to claim 1, wherein at least one cell signaling chemical is rhodamine 123 and/or methyl 3-hydroxypalmitate. 6. The method according to claim 1, wherein the sewage substrate is in a sewage catchment network or in a sewage treatment plant. 7. The method according to claim 1, wherein the modulated activity is selected from the group consisting of cell-to-cell communication, threshold sensitivity, group swimming, bacterial motility, symbiotic relationship with multicellular organisms, cellular metabolic rate, metabolite Production, cell division and association, cell resuscitation, formation of biofilm colonies, entry into quiescence or dormancy, discrete and diverse metabolic processes consistent with cell density, production of antibiotics, production of surfactants, and bioluminescence. 8. The method according to claim 1, wherein the microbiota is selected from the group consisting of Gram-positive bacteria, Gram-negative bacteria, cyanobacteria, autotrophic bacteria, heterotrophic bacteria and nitrogen-fixing bacteria. 9. The method according to claim 1, wherein the microbial population is selected from the group consisting of sulfur reducing bacteria, sulfate reducing bacteria, bacteria converting sulfide to sulfate, ammonia producing bacteria, nitrite producing bacteria, nitrate producing bacteria, denitrifying bacteria Bacteria and methane producing bacteria. 10. The method according to claim 1, wherein the activity of the microbiota is upregulated, initiated or maintained by adding at least one cell signaling chemical. 11. The method according to claim 12, wherein at least one cell signaling chemical agent is selected from the group consisting of N-acyl homoserine lactones; histidine protein kinase pheromones; N-acetylated, C-amidated D-amino acid hexapeptides ; D-amino acid peptides including D-isoleucine and/or D-tyrosine; cyclic dipeptides; hydrophobic tyramines; fatty acid derivatives; furanones; ester. 12. The method according to claim 11, wherein the cell signaling chemical agent is an N-acyl homoserine lactone. 13. The method according to claim 1, wherein the activity of the microbiota is downregulated by adding or reducing the signal strength of at least one cell signaling chemical. 14. The method according to claim 13, wherein at least one cell signaling chemical agent is selected from N-acyl homoserine lactone; histidine protein kinase pheromone; N-acetylated, C-amidated D-amino acid hexapeptide ; D-amino acid peptides including D-isoleucine and/or D-tyrosine; Cyclic dipeptides; Hydrophobic tyramines; Fatty acid derivatives; Halogenated, hydroxylated or alkyl furanones; Furanones ; rhodamine 123 and methyl 3-hydroxypalmitate. 15. The method according to claim 14, wherein the cell signaling chemical agent is a halogenated, hydroxylated or alkylfuranone. 16. The method according to claim 1, wherein adding at least one cell signaling chemical agent modulates gene expression of the microorganism. 17. The method according to claim 16, wherein the gene expression of the microorganism is for the control of luminescence or the production of toxins, antibiotics, enzymes, polysaccharides and surfactants. 18. The method according to claim 1, wherein the activity of anaerobic and aerobic microbiota is up-regulated or down-regulated, and at least one cell signaling chemical agent is selected from N-(3-oxohexanoyl)-L-homo Serine lactone, 3-Oxydecanoyl homoserine lactone, N-butyryl-L-homoserine lactone, Zeatin, 6-(γγ-dimethylallylamino)purine, 6-benzylamino-purine . 19. The method according to claim 1, wherein the activity of sulfur reducing bacteria is down-regulated, and at least one cell signaling chemical is selected from the group consisting of N-(3-oxohexanoyl)-L-homoserine lactone, 3-decane oxide Acyl homoserine lactone, N-butyryl-L-homoserine lactone, zeatin, 6-(γγ-dimethylallylamino)purine, 6-benzylamino-purine, 3-hydroxypalmitic acid methyl Esters, Comb Moss Extract, Cytokinin, Indole-3-Acetic Acid, Rhodamine 123, 3-Oxo-Decanoyl Homoserine Lactone, Butyryl Homoserine Lactone, and Mixtures thereof. 20. The method according to claim 1, wherein the activity of sulfur reducing bacteria is down-regulated and the at least one cell signaling chemical is selected from the group consisting of halogenated furanones, hydroxylated furanones, alkylfuranones, and mixtures thereof. 21. The method according to claim 1, wherein at least one cell signaling chemical is added in a single amount. 22. The method according to claim 1, wherein at least one cell signaling chemical is added continuously or intermittently. 23. The method of claim 1, wherein at least one cell signaling chemical is added to the sewage substrate of the sewage catchment network. 24. The method according to claim 1, wherein at least one cell signaling chemical is added to the sewage substrate of a sewage treatment plant. 25. A method for reducing odor in a sewage treatment system, comprising: adding at least one cell signaling chemical agent to the sewage treatment system, wherein at least one cell signaling chemical agent regulates gene expression in microbial cells or regulates microbial cells or Communication signals between microbial cell populations to inhibit the activity of odor-producing microorganisms or to promote the activity of other microbial populations in wastewater treatment systems so that other microbial populations outcompete odor-forming bacteria using the same food source. 26. The method according to claim 25, wherein the odor producing microorganisms are sulfur or sulfate reducing bacteria or ammonia producing bacteria. 27. The method according to claim 25, wherein at least one cell signaling chemical is selected from bacterial pheromones or eukaryotic hormones. 28. The method according to claim 25, wherein at least one cell signaling chemical agent is selected from the group consisting of N-(3-oxohexanoyl)-L-homoserine lactone, 3-oxodecanoyl homoserine lactone, N-butyl Acyl-L-homoserine lactone, zeatin, 6-(γγ-dimethylallylamino)purine, 6-benzylaminopurine, 3-hydroxypalmitic acid methyl ester, comb moss extract, cytokinin , indole-3-acetic acid, rhodamine 123, 3-oxo-decanoyl homoserine lactone, butyryl homoserine lactone and mixtures thereof. 29. The method according to claim 25, wherein the cell signaling chemical agent is selected from the group consisting of halogenated furanones, hydroxylated furanones, alkylfuranones, and mixtures thereof. 30. A method of reducing or preventing corrosion in a sewage treatment system, comprising: adding at least one cell signaling chemical to a sewage treatment system, wherein at least one cell signaling chemical acts by modulating gene expression in microbial cells or modulating Occasional communication signals between microbial cell populations to inhibit the activity of microorganisms that convert sulfide to sulfate. 31. A method of inhibiting biofilm formation or maintenance in a sewage catchment network, comprising: adding at least one cell signaling chemical agent to a sewage substrate in a sewage catchment network, wherein at least one cell signaling chemical agent regulates microbial cell The expression of genes within or regulating the communication signals between microbial cells or between microbial cell populations can inhibit the group swimming, threshold sensitivity or biofilm attachment of microbial populations. 32. The method according to claim 31, wherein at least one cell signaling chemical is selected from bacterial pheromones or eukaryotic hormones. 33. The method according to claim 31, wherein at least one cell signaling chemical agent is selected from the group consisting of N-acyl homoserine lactones; pheromone peptides; N-acetylated, C-amidated D-amino acid hexapeptides; comprising D - D-amino acid peptides of isoleucine and/or D-tyrosine; cyclic dipeptides; hydrophobic tyramines; fatty acid derivatives and furanones. 34. The method according to claim 33, wherein at least one cell signaling chemical agent is selected from halogenated, hydroxylated or alkylfuranones. 35. The method according to claim 31, wherein the at least one cell signaling chemical agent is selected from the group consisting of 3-oxodecanoyl homoserine lactone, butyryl homoserine lactone, extracts of Combium Combat and mixtures thereof. 36. The method according to claim 31, wherein the cell signaling chemical down-regulates the production of lipoprotein biosurfactant in the microbial population. 37. The method according to claim 31, wherein the cell signaling chemical down-regulates polysaccharide production in the microbial population. 38. A method of promoting microbial digestion of sewage in a sewage treatment plant, comprising: adding at least one cell signaling chemical agent to the sewage substrate of a sewage treatment plant or sewage catchment network, wherein at least one cell signaling chemical agent is activated during sewage treatment In the method, the activity of aerobic, anaerobic and facultative anaerobic bacteria is enhanced at selected locations by modulating gene expression within microbial cells or modulating communication signals between microbial cells or populations of microbial cells. 39. The method according to claim 38, wherein at least one cell signaling chemical agent is selected from the group consisting of N-acyl homoserine lactones; pheromone peptides; N-acetylated, C-amidated D-amino acid hexapeptides; comprising D - D-amino acid peptides of isoleucine and/or D-tyrosine; cyclic dipeptides; hydrophobic tyramines; fatty acid derivatives and furanones. 40. The method according to claim 38, wherein the cell signaling chemical agent is N-acyl homoserine lactone; N-acetylated, C-amidated D-amino acid hexapeptide or a mixture thereof. 41. A method of controlling biogas production in a sewage treatment plant, comprising: adding at least one cell signaling chemical agent to a sewage catchment network or sewage substrate of a sewage treatment plant, wherein at least one cell signaling chemical agent regulates microbial intracellular The expression of genes or the regulation of communication signals among microbial cells or groups of microbial cells to enhance or inhibit the activity of anaerobic, methane-forming bacteria. 42. A method of promoting digestion of sewage sludge, comprising: adding at least one cell signaling chemical to a sewage substrate, wherein at least one cell signaling chemical acts by modulating gene expression in microbial cells or modulating microbial cells or populations of microbial cells Communication signals between cells to enhance the activity of aerobic or anaerobic bacteria. 43. The method according to claim 42, wherein at least one cell signaling chemical agent is selected from the group consisting of N-acyl homoserine lactone, zeatin, 6-(γγ-dimethylallylamino)purine, 6-benzylamino- Purines, cytokinins, indole-3-acetic acid, rhodamine 123. 44. A method for reviving dormant microorganisms or microorganisms in a starvation or stationary phase in a sewage substrate, comprising: adding at least one cell signaling chemical agent to the sewage substrate, wherein at least one cell signaling chemical agent regulates genes in microbial cells Expresses or modulates communication signals between microbial cells or populations of microbial cells to stimulate the activity of dormant, starved or stable microorganisms. 45. A method according to claim 44, wherein the cell signaling chemical is a furanone involved in communication with N-acyl homoserine lactones or peptide pheromones or mixtures thereof. 46. A method of controlling bacteria that cause oxidation or reduction of nitrogenous compounds in a sewage substrate, comprising: adding at least one cell signaling chemical to the sewage substrate, wherein the at least one cell signaling chemical acts by modulating genes in microbial cells Expressing or modulating a communication signal between microbial cells or populations of microbial cells to regulate the activity of ammonia-producing bacteria, nitrite-producing bacteria, nitrous oxide-producing bacteria, nitrate-producing bacteria, or denitrifying bacteria. 47. The method according to claim 46, wherein at least one cell signaling chemical agent is selected from the group consisting of halogenated furanones, hydroxylated furanones, alkylfuranones, N-acyl homoserine lactones, peptide pheromones and mixtures thereof. 48. The method according to claim 46, wherein at least one cell signaling chemical agent is selected from the group consisting of 3-oxodecanoyl homoserine lactone, butyryl homoserine lactone, and mixtures thereof. 49. A method of reducing microbial activity in a sewage catchment network comprising: Adding at least one cell signaling chemical agent to the sewage substrate in the sewage catchment network, wherein adding at least one cell signaling chemical agent to the sewage catchment network regulates gene expression in microbial cells or regulates microbial cells or Signaling between microbial cell populations to down-regulate the microbial activity of one or more bacteria, be they aerobic, facultatively anaerobic, or anaerobic, in a sewage substrate.

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